Sensitive Detection of a Nerve-Agent Simulant through Retightening Internanofiber Binding for Fluorescence Enhancement.

In this work, we develop fluorescent hierarchical nanofiber bundles 1, which involve the internanofiber hydrogen-bonding interactions, for rapid and sensitive detection of diethyl chlorophosphate (DCP) vapor. First, the internanofiber hydrogen-bonding strength can be weakened by photoexcitation, which thereby increases the internanofiber spacing and decreases the fluorescence intensity. Then, when exposed to trace DCP vapor, the strong interactions between DCP and hydroxyl groups on the nanofibers can effectively retighten the nanofibers and enhance the fluorescence as the detection signal. In contrast, the interferences, such as common organic solvents, cannot retighten nanofiber bundles 1 because of the lack of strong interactions with the nanofibers. On the basis of this novel detection mechanism, fluorescence detection of DCP with rapid signal response (ca. 3 s) and high sensitivity (15 ppb) is achieved.